4123:1-17-04
Roof car suspended platforms - window cleaning.

(1)
The horizontal speed of a roof car shall
be no more than fifty feet per minute.

(2)
A roof car may not be moved horizontally
unless means are in place to prevent the car from moving outside the areas
provided for roof car travel.

(3)
The roof car shall be designed and installed in such a manner as to remain
stable and upright under every loading condition.

(4)
A roof car shall be so positioned and
anchored to the structure as to insure that the working platform is placed and
retained in proper position for vertical travel.

(5)
The operating device controlling movement
of a roof car shall be of the continuous pressure weather-proof electric type
and shall be located on the roof car, the working platform, or both. If located
on both, such operating devices shall be interlocked so that control is
possible only from one at a time.

(6)
The operating device controlling movement
of a roof car shall not be operable until the working platform is at its
uppermost position for travel and is not in contact with the building face or
fixed vertical guides in the face of the building, and until all protective
devices and interlocks are in a position for movement.

(7)
If the access to the roof car at any
point of its travel is not over the roof area, standard guardrails with
self-closing, self-locking gates shall be provided on the roof car.

(3)
The vertical speed of a working platform
suspended by four or more hoisting ropes shall be no more than seventy-five
feet per minute.

(4)
The vertical
speed of a working platform suspended by less than four hoisting ropes shall be
no more than thirty-five feet per minute.

(5)
The working platform shall be no less
than twenty-four inches wide.

(6)
The working platform shall be provided with toeboards and with permanent
guardrails no less than thirty-six inches high, and no more than forty-two
inches high at the front (building side). At the rear, and on the sides, a
standard guardrail and toeboard shall be provided. An intermediate guardrail
shall be provided around the entire platform between the top guardrail and the
toeboard.

(8)
Where access gates are provided, they
shall be self-closing and self-locking. Such gates are required where access to
the working platform is not over the roof area.

(9)
A means shall be provided to prevent
inadvertent horizontal movement of the working platform.

(10)
The operating device controlling
vertical movement of the working platform shall be located on the working
platform and shall be of the continuous pressure weatherproof electric type.

(11)
The operating device
controlling vertical movement shall be operable only when all electrical
protective devices and interlocks on the working platform are in normal
operating position, and the roof car is at an established operating point.

(12)
On roof-powered platforms, an
emergency electric operating device shall be provided near the hoisting machine
for use in the event of failure of the normal operating device for the working
platform or failure of the traveling cable system. This emergency device shall
be mounted in a locked compartment and shall have a legend mounted thereon
reading: "For Emergency Operation Only. Establish Communication With Personnel
On Working Platform Before Use." A key for unlocking the compartment housing
the emergency operating device shall be mounted in a break-glass receptacle
located near the device.

(1)
Each hoisting rope shall be made of wire
and shall be no less than five-sixteenths-inch diameter.

(2)
Working platforms shall be suspended by
no less than two ropes with a safety factor often as calculated under the
following formula:

F = S x N / W

Where

S = manufacturer's rated breaking strength of one rope

N = number of ropes under load

W = maximum static load on all ropes with the platform and its
rated load at any point of its travel

(3)
Where winding drums are used, the rope
shall be wound in level layers.

(4)
Winding drums shall have no less than
three turns of rope remaining when the working platform is at its lowest
possible point of travel.

(5)
Where the working platform is suspended by more than two ropes, the nondrum
ends of the ropes shall be provided with individual shackle rods which will
permit individual adjustment of rope lengths.

(6)
The lengthening or repairing of wire
ropes by splicing is prohibited.

(8)
Wire rope
shall not be used if, in any length of eight diameters, the total number of
visible broken wires exceeds ten per cent of the total number of wires, or if
the rope shows other signs of excessive wear, corrosion, or defect.

(1)
Electrical protective devices and
interlocks shall be of the weather-proof type.

(2)
When a traveling cable storage reel is
used, an electric contact shall be provided and so connected that it will cause
the relay for vertical travel to open if the tension on the traveling cable
exceeds safe limits.

(3)
An
automatic overload device shall be provided to cut off electrical power to the
circuit in all hoisting motors for travel in the up direction, should the load
applied to the hoisting ropes at either end of the working platform exceed one
hundred twenty-five per cent of its normal tension with rated load as shown on
the manufacturer's data plate on the working platform.

(4)
An automatic device shall be provided for
each hoisting rope which will cut off electrical power to the hoisting motor or
motors in the down direction and will apply the brakes if any hoisting rope
becomes slack.

(5)
Upper and lower
directional limit devices shall be provided to prevent the travel of the
working platform beyond the normal upper and lower limits of travel.

(6)
Directional limit devices, if driven from
the hoisting machine by chains, tapes, or cables, shall incorporate a device to
disconnect the electric power from the hoisting machine and apply both the
primary and secondary brakes in the event of failure of the driving means.

(7)
On platforms with four or more
ropes, final terminal stopping devices for the working platform shall be
provided as a secondary means of preventing the working platform from
over-traveling at the terminals.

(8)
Emergency stop switches shall be provided
in or adjacent to each operating device.

(9)
Electrical cord strain relief anchors and
grip or equivalent means shall be provided to prevent the electrical cord from
pulling on the receptacle.

A safety belt or harness with means for attachment to a
lifeline on the roof or to the working platform shall be provided for each
employee on a working platform suspended by less than four wire ropes.